This report covers the grainfilling period and harvest of winter-spring rice, followed by planting of summer-autumn rice in the Mekong Delta and the southeast of Vietnam. In the central part, winter rice was also followed by summer rice, but planting took place in April only. In the north, winter-spring rice was planted in January. It will be ready for harvest in May.

The proportion of irrigated cropland in Vietnam is 32%, which means that precipitation is vital to the production of most crops in Vietnam. The agro-climatic condition showed the TEMP (21.2°C, +0.5°C) and the RADPAR (1022 MJ/m², +5%) were both above the average. But due to the decreased precipitation (241 mm, -23%), the BIOMASS (726 gDM/m², -8%) dropped below the 15YA. The VCIx was 0.89, and the CALF (96%, 0%) was at the 5YA. The CPI in this monitoring period was 1.10, which represents a normal crop production situation.

Based on the NDVI development graph, the crop conditions were below the 5YA throughout the whole monitoring period except at the beginning of January, but the NDVI value was always above 0.5 throughout the monitoring period. In most of January and February, the precipitation was generally near or surpassed the 15YA . While in March and April, the precipitation was below the average. The temperature fluctuated around the average throughout the monitoring period. Especially in late March and all of  April, the temperatures surpassed the average. As to the spatial distribution of NDVI profiles, the crop conditions in most of the country were near the average.  Due to the significant decrease in precipitation during the monitoring period, the crop conditions in Vietnam are fair.

Regional analysis

Based on cropping systems, climatic zones, and topographic conditions, the following agro-ecological zones (AEZ) can be distinguished for Vietnam: Central Highlands (213), Mekong River Delta (214), North Central Coast (215), North East (216), North West (217), Red River Delta (218), South Central Coast (219) and South East (220) .  

In the Central Highlands, the RAIN (224 mm, -14%) and the TEMP (21.9°C, -0.2°C) were both below the average, but the RADPAR (1149 MJ/m², 1%) had a slight increase. The resulting BIOMASS (737 gDM/m², 0%) was at the level of the 15YA. According to the NDVI development graph, crop conditions were generally near the 5YA during the whole monitoring period. The CALF was 97% and VCIx was 0.80. The CPI was 1.00, which indicates that the crop production situation was normal. The crop conditions in this region are expected to be near the average.

In the Mekong River Delta region, the TEMP (27.2°C, -0.2°C) was below the average. The RAIN (315 mm, 0%) and RADPAR (1228 MJ/m², 2%) were at the level of 15YA. The BIOMASS (950 gDM/m², 6%) was above average. The CALF was 87% and the VCIx was 0.89. The crop condition development graph showed that the crop conditions were close to the 5YA. The CPI was 1.12, which indicates that the crop productions were slightly better than the average. Overall, the crop conditions in this region are expected to be average.

In the North Central Coast, although the TEMP (19.7°C, 0.4°C) and the RADPAR (941 MJ/m², 6%) were above the average, due to the sharp decrease of RAIN (280 mm, -24%), the BIOMASS (760 gDM/m², -9%) was below the average. CALF was 99% and the VCIx was 0.93. According to the crop condition development graph, the NDVI was below the average in most of the monitoring period, and there was a sharp drop in February, which may have been caused by the cloud cover in the satellite images. The CPI was 1.10. The crop conditions in this region are expected to be below the average due to the impacts of rainfall deficit. 

In the North East region, the TEMP (18.0°C, 1.2°C) increased by 1.2°C and the RADPAR (785 MJ/m², 11%) increased by 11%. However, similar to the situation in the North Central Coast, the RAIN (191 mm, -44%) showed a sharp decrease which caused a drop in  BIOMASS (599 gDM/m², -21%). The CALF was 99% and the VCIx was 0.95. According to the NDVI development graph, crop conditions fluctuated greatly. The NDVI was above the average in January and the late February. At the rest of the monitoring time, the NDVI was below the average.  The CPI was 1.08. The crop conditions were expected to be lower than the average.

In the North West region, the TEMP (18.3°C, 1.0°C) was above the average. Although the RADPAR (1034 MJ/m², 8%) increased by 8%, the BIOMASS (493 gDM/m², -28%) dropped by 28%, which was   due to the decrease of RAIN (115 mm, -56%). The VCIx was 0.88 and the CALF was 100%. The CPI was 0.99. The crop condition development graph showed that NDVI was below average. The crop conditions in this region are expected to be unfavorable due to the drought.

In the region of the Red River Delta, the TEMP (19.9°C, 0.7°C) increased by 0.7°C and the RADPAR (714 MJ/m², 11%) increased by 11%. With the heavy decrease of RAIN (194 mm, -39%), the BIOMASS (634 gDM/m², -18%) dropped by 18%. The CALF was 95% and the VCIx was 0.88. As shown by the crop condition development graph, the NDVI fluctuated greatly. In early January and late February, the NDVI was at or surpassed the maximum of the past 5 years. The CPI was 1.10. The crop conditions in this region were estimated to be below average due to the rainfall deficit. 

In the South Central Coast, the RAIN (406 mm, -4%) was lower than the 15YA. But with the RADPAR (1060 MJ/m², 2%) close to the average and the TEMP (21.0°C, 0.6°C) increased by 0.6°C, the resulting BIOMASS (903 gDM/m², 2%) showed a slight increase by 2%. The CALF was 98% and the VCIx was 0.91. The crop condition development graph showed that during the whole monitoring period, the NDVI was close to the average except in late January and February. There were two sharp drops during this period, which may have been due to cloud cover in the satellite images. The CPI was 1.10. Overall, the crop conditions in this region were normal.

In the South East region, TEMP (26.0°C, 0.0°C) was at the level of 5YA and RADPAR (1253 MJ/m², 5%) increased by 5%. With a significant increase of RAIN (278 mm, 11%), the BIOMASS (795 gDM/m², 3%) increased by 3%. The CALF was 94% and the VCIx was 0.80. The crop condition development graph indicates that NDVI was a slightly lower than the average. The CPI was 1.02. The crop conditions in this region are expected to be comparable to the five-years average.

Figure3.46 Vietnam's crop conditions, January -May 2023

(a) . Phenology of major crops

(b) Crop condition development graph based on NDVI

(c)  Maximum VCI

                (d) Spatial NDVI patterns compared to 5YA                           (e) NDVI profiles

                                 (f) Rainfall profiles                                                                                       (g) Temperature profiles

(h) Crop condition development graph based on NDVI Central Highlands Vietnam (left), and Mekong River Delta (right)

(i) Crop condition development graph based on NDVI North Central Coast Vietnam (left), and North East Vietnam (right).

(j) Crop condition development graph based on NDVI North West Vietnam (left), and Red River Delta (right).

 (k) Crop condition development graph based on NDVI South Central Coast Vietnam (left), and South East Vietnam (right).

Table3.84 Vietnam's agroclimatic indicators by sub-national regions, current season's values and departure from 15YA, January 2023-April 2023

Table3.85 Vietnam's agronomic indicators by sub-national regions, current season's values and departure from 5YA, January 2023-April 2023